doctest: Doctest is not able to compile on OSX

Description

I am trying to get my Travis CI build working with doctest (I’m switching from Catch to this for performance), but my build is not working on OSX (It is for Linux). In my Travis CI logs, I see the following error:

Undefined symbols for architecture x86_64:
  "std::__1::basic_ostream<char, std::__1::char_traits<char> >& std::__1::operator<<<char, std::__1::char_traits<char>, std::__1::allocator<char> >(std::__1::basic_ostream<char, std::__1::char_traits<char> >&, std::__1::basic_string<char, std::__1::char_traits<char>, std::__1::allocator<char> > const&)", referenced from:
      doctest::String doctest::detail::stringifyBinaryExpr<std::__1::basic_string<char, std::__1::char_traits<char>, std::__1::allocator<char> >, char [6]>(std::__1::basic_string<char, std::__1::char_traits<char>, std::__1::allocator<char> > const&, char const*, char const (&) [6]) in hello_world_test.cpp.o
ld: symbol(s) not found for architecture x86_64
clang: error: linker command failed with exit code 1 (use -v to see invocation)
make[2]: *** [test/test_runner] Error 1
make[1]: *** [test/CMakeFiles/test_runner.dir/all] Error 2
make: *** [all] Error 2

Steps to reproduce

I’m using CMake, and my invocation command is:

cmake -DCMAKE_BUILD_TYPE=$BUILD_TYPE -DCMAKE_CXX_COMPILER=$COMPILER -DBUILD_TESTS=ON ..

(COMPILER is set to clang++ and BUILD_TYPE is set to Debug and Release, both of which fail)

The CMake configuration I am using is (for flags):

if (CMAKE_CXX_COMPILER_ID MATCHES "Clang" OR CMAKE_CXX_COMPILER_ID STREQUAL "GNU")
    set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -Wall -Wextra -Werror")
    set(CMAKE_CXX_FLAGS_DEBUG "${CMAKE_CXX_FLAGS_DEBUG} -g")
    set(CMAKE_CXX_FLAGS_RELEASE "${CMAKE_CXX_FLAGS_RELEASE} -O2")
elseif (CMAKE_CXX_COMPILER_ID STREQUAL "MSVC")
    # ...
endif(CMAKE_CXX_COMPILER_ID MATCHES "Clang" OR CMAKE_CXX_COMPILER_ID STREQUAL "GNU")

And the test configuration:

set(TEST_SOURCES
    factorial_test.cpp
    hello_world_test.cpp
)

add_library(doctest INTERFACE)
target_include_directories(doctest INTERFACE 
    "${CMAKE_SOURCE_DIR}/third_party/doctest" # Contains single header
)

add_executable(test_runner test_runner.cpp ${TEST_SOURCES})
target_link_libraries(test_runner Project-Name-lib doctest)

add_test(all_tests test_runner)

Extra information

doctest version: v1.2.8
Operating System: Travis CI OSX XCode image 9.2
Compiler+version: AppleClang 9.0.0.9000039

About this issue

Original URL
State: closed
Created 6 years ago
Comments: 23 (10 by maintainers)

Commits related to this issue

Fix Building Error on macOS Fix the following building error on macOS. ``` Undefined symbols for architecture x86_64: "std::__1::basic_ostream<char, std::__1::char_traits<char> >& std::__1::operato... — committed to jacobdufault/cquery by xu-cheng 6 years ago
finally resolved issue #126 and #143 "properly" - turns out the problem is this: when using clang from xcode - that means libc++. in that case I include <iosfwd> instead of forward-declaring std::ostr... — committed to doctest/doctest by onqtam 6 years ago
finally resolved issue #126 and #143 "properly" - turns out the problem is this: when using clang from xcode - that means libc++. in that case I include <iosfwd> instead of forward-declaring std::ostr... — committed to doctest/doctest by onqtam 6 years ago
Apple Clang fix See https://github.com/onqtam/doctest/issues/126 — committed to potatoengine/potato by seanmiddleditch 5 years ago
fixed #126 — committed to doctest/doctest by onqtam 5 years ago
Fix unit tests on macos See https://github.com/onqtam/doctest/issues/126 — committed to Ghabry/easyrpg-player by Ghabry 4 years ago
Fix unit tests on macos See https://github.com/onqtam/doctest/issues/126 — committed to Ghabry/easyrpg-player by Ghabry 4 years ago
Fix unit tests on macos See https://github.com/onqtam/doctest/issues/126 — committed to Ghabry/easyrpg-player by Ghabry 4 years ago
following https://github.com/onqtam/doctest/issues/126 — committed to DerThorsten/xtl by DerThorsten 3 years ago
for clang with libc++ always using std headers instead of forward declaring anything from std - hopefully fixing #126 and #356 at last — committed to doctest/doctest by onqtam 3 years ago
for clang with libc++ always using std headers instead of forward declaring anything from std - hopefully fixing #126 and #356 at last — committed to clapdb/doctest by onqtam 3 years ago

Most upvoted comments

@arnavb finally resolved “properly” - turns out the problem is this: when using clang from xcode - that means libc++. in that case I include <iosfwd> instead of forward-declaring std::ostream myself. Then if the user includes somewhere only the doctest header and <string> and then does a comparison - then and only then will there be some linker issue which we resolved by including <iostream> in the tests. This is a toolchain issue when using the <iosfwd> header - the details are still not clear to me but I managed to get the linker to pull in what is necessary by adding a dummy unused global function in the implementation of doctest that uses operator<< of std::string to print to std::cout.

the <iostream> header should no longer be necessary - try the version of the header from the dev branch (soon to be released in master as version 2.0!)

onqtam on Jan 13, 2019

Gosh… I’ll find a way to “fix” it - perhaps either with some magic attribute to that function or by calling it somewhere within doctest (after making it noinline so it doesn’t get inlined and optimized out)

onqtam on May 14, 2019

@onqtam You’re right. I added <iostream> and it works! (Finally). However, this solution is ugly on more than one level. <string> is supposed to have a complete version of std::string since that’s what the header is for! Why is <iostream>, which only probably including <string> itself, solving a LINKING PROBLEM while the header that implements std::string isn’t? 😶

😖

On a side note…

I really want to thank you for all of your help with this issue! I know it must be hard to take time out of your busy schedule as you mentioned before to help a problem that as we found out isn’t even caused by doctest! Many others would just reject people with such problems and I appreciate your help as such. Thanks again!

I’m going to enjoy using doctest (especially the performance boost 😛) and will definitely recommend it to others.

arnavb on Apr 16, 2018

@onqtam Ok Update. I’ve created another repository in which I’m trying to use doctest on OSX, and … it works fine! Now I have to figure out the difference between it and my repository. The repository is here: https://github.com/arnavb/osx-doctest

arnavb on Apr 16, 2018

@onqtam Thanks for the quick reply. I’ll keep trying to fix this … somehow. For now, I’m going to isolate this issue by remove all extraneous details and then see if the build works. Thanks for that note about the REQUIRE asserts. Turns out, I actually needed CHECK asserts all along (I just found out the difference recently).

arnavb on Apr 16, 2018